The good news is, that you can still find that the information existed. The bad news is that you cannot rely on VIAF to persist in keeping all the information it collects.

Finding information about people who are significant in the history of countries like Egypt or Turkey is not easy. Probably there are other repositories that include people like Mr al-Misri. When they exist, they should be referenced as well in Wikidata.

I did add a few statements to Wikidata, many more could be added based on the information in the Wikipedia articles. I did not do this because it would side track me too much from other things.
Thanks,
GerardM